Ferromagnetic materials which are used in conventional magnetic recording media such as audio tapes, video tapes, memory tapes, magnetic sheets and magnetic cards are, for example, fine particles of ferromagnetic iron oxide, cobalt ferrite, ferromagnetic chromium dioxide or fine ferromagnetic metal particles or a thin film of ferromagnetic metal. One of the modern magnetic recording systems that is attracting research attention is high-density recording of short-wave signals. This system requires a ferromagnetic material having magnetic properties suitable for high-density recording (e.g., higher coercive force and greater residual flux density), and a ferromagnetic metal material is considered to be the most promising. However, the higher the coercive force and/or the residual flux density of magnetic particles, the greater the interaction between the individual particles, thus making it difficult to form a uniform dispersion of the magnetic particles. When metallic alloy particles are used as ferromagnetic particles, they are easily oxidized in nature, and, therefore, the magnetic properties of alloyed metal ferromagnetic particles are more easily deteriorated with time than oxide-based magnetic particles.